Found a short and concise Dhamma article by Bhante Subhuti that discussed about whether Buddha lives in Nibbana, as well as the two prevalent wrong views: Eternalism and Nihilism.
Let's understand what the "I" is (Body & mind) aggregate
It's 5 Skandhas
The five aggregates or heaps of clinging are:
1) Body form (or material image, impression) (rupa)
2) sensations (or feelings, received from form) (vedana)
3) perceptions (sanya)
4) Thoughts/mental volitions/ mental activity or formations (sankhara)
5) consciousness (vinyana)
The Suttas tells us that Nibbana is the absence "perceptions" and "feelings" state is reached while alive
"Patticcasammupada" tells us that we "stop" sankharas we are progressing towards Nibbana
So here "sankhara" and "vinyana" consciousness (both conscious & sub-conscious vinyana) is also done with?
So what remains just the "body" as long as the push of the past is there
Then even that is finished once this life is done
Buddha gives an example of "fire" going out MN 72
What happens to one who has fully realized Nibbana?
[Aggivessana Vacchagotta:] "But, Master Gotama, the monk whose mind is thus released: Where does he reappear?"
"In that case, Master Gotama, he does not reappear."
"'Does not reappear,' Vaccha, doesn't apply."
"...both does & does not reappear."
"...doesn't apply."
"...neither does nor does not reappear."
"...doesn't apply."
"How is it, Master Gotama, when Master Gotama is asked if the monk reappears... does not reappear... both does & does not reappear... neither does nor does not reappear, he says, '...doesn't apply' in each case. At this point, Master Gotama, I am befuddled; at this point, confused. The modicum of clarity coming to me from your earlier conversation is now obscured."
"Of course you're befuddled, Vaccha. Of course you're confused. Deep, Vaccha, is this phenomenon, hard to see, hard to realize, tranquil, refined, beyond the scope of conjecture, subtle, to-be-experienced by the wise. For those with other views, other practices, other satisfactions, other aims, other teachers, it is difficult to know. That being the case, I will now put some questions to you. Answer as you see fit. What do you think, Vaccha: If a fire were burning in front of you, would you know that, 'This fire is burning in front of me'?"
"...yes..."
"And suppose someone were to ask you, Vaccha, 'This fire burning in front of you, dependent on what is it burning?' Thus asked, how would you reply?"
"...I would reply, 'This fire burning in front of me is burning dependent on grass & timber as its sustenance.'"
"If the fire burning in front of you were to go out, would you know that, 'This fire burning in front of me has gone out'?"
"...yes..."
"And suppose someone were to ask you, 'This fire that has gone out in front of you, in which direction from here has it gone? East? West? North? Or south?' Thus asked, how would you reply?"
"That doesn't apply, Master Gotama. Any fire burning dependent on a sustenance of grass and timber, being unnourished — from having consumed that sustenance and not being offered any other — is classified simply as 'out' (unbound)."
"Even so, Vaccha, any physical form by which one describing the Tathagata would describe him: That the Tathagata has abandoned, its root destroyed, made like a palmyra stump, deprived of the conditions of development, not destined for future arising. Freed from the classification of form, Vaccha, the Tathagata is deep, boundless, hard to fathom, like the sea. 'Reappears' doesn't apply. 'Does not reappear' doesn't apply. 'Both does & does not reappear' doesn't apply. 'Neither reappears nor does not reappear' doesn't apply.
"Any feeling... Any perception... Any mental fabrication...
"Any consciousness by which one describing the Tathagata would describe him: That the Tathagata has abandoned, its root destroyed, made like a palmyra stump, deprived of the conditions of development, not destined for future arising. Freed from the classification of consciousness, Vaccha, the Tathagata is deep, boundless, hard to fathom, like the sea."
Bhante Subhuti that discussed about whether Buddha lives in Nibbana, as well as the two prevalent wrong views: Eternalism and Nihilism.